1. Field of the Invention
The present invention relates to a recording medium feed apparatus for feeding a recording medium into a housing of an image recording apparatus by means of a manual feed tray provided openably and closably with respect to the housing of the image recording apparatus.
2. Description of the Related Art
An image recording apparatus for recording an image on a recording medium such as paper is often designed so that a recording medium can be fed (supplied) not only from a paper feed cassette built in a housing of the image recording apparatus but also from a manual feed tray provided openably and closably in a side surface of the housing. In such recording medium feed apparatus using a manual feed tray, a feed roller for separating and feeding (supplying) recording media one by one is disposed to abut against a recording medium mounting surface of the manual feed tray. The recording media are inserted between the feed roller and the manual feed tray so as to push up the feed roller. Thus, the feed roller abuts against the uppermost recording medium.
Therefore, in order to always bring the feed roller in such a manual feed tray into contact with the uppermost recording medium regardless of the number of recording media stacked thereon, for example, a swinging unit for swinging a feed roller 32 provided in the front end of a pendulum arm 71 rotatable around a pivot axis portion 70 is used as shown in FIG. 12A. To swing the arm 71, a certain length (L) in the feed (paper feed) direction has to be secured to install the feed roller unit having the feed roller 32 and the arm 71. Accordingly, when the feed roller unit is disposed inside the housing 4 near the manual feed tray, there occurs a problem that a space to be occupied inside the housing 4 by the other units is reduced, or miniaturization of the housing as a whole is prevented.
In order to reduce the space occupied by the feed roller unit inside the housing (for example, to reduce the length required for installation thereof into L/2), it can be considered that the arm 71 of the feed roller unit is shortened as shown in FIG. 12B, or the pivot axis portion 70 of the pendulum arm 71 is disposed as closely to the housing side surface as possible to thereby reduce the occupied space as shown in FIG. 12C. When the arm 71 is shortened as shown in FIG. 12B, a contact position Q of the feed roller with the uppermost recording medium P is shifted largely (ΔL) upstream or downstream in the feed (paper feed) direction in accordance with the number of stacked recording media P (the total thickness of the recording media). Thus, stability in feeding (supplying) the recording media is lowered. On the other hand, assume that the pivot axis portion 70 of the pendulum arm 71 is disposed as closely to the housing side surface as possible as shown in FIG. 12C. The arm angle of the feed roller unit abutting against the manual feed tray 30 when the length of the arm 71 is not reduced is an angle θ4 in the case shown in FIG. 12A, while the angle is increased to an angle θ5 (>θ4) in the case shown in FIG. 12C. Thus, the load to depress the paper (recording media) increases so that a trouble such as double paper feed in which two or more sheets of paper are fed simultaneously is apt to occur in the recording medium feed (paper feed).
In order to solve the foregoing problem without shortening the arm or disposing the pivot axis portion of the arm as closely to the housing side surface as possible in such a manner, for examples, JP-A-H11-171360 discloses a configuration in which a frame having a feed roller unit attached thereto and a manual feed tray are linked by a link so that the feed roller unit is rotated and displaced largely between a driving position and a housing position of the feed roller unit in accordance with the open/close operation of the manual feed tray.
In JP-A-H11-171360, a feed roller (referred to as “pickup roller” in JP-A-H11-171360) is provided in a front end portion of the arm of the feed roller unit, while a conveyance roller (referred to as “paper feed roller” in JP-A-H11-171360) is provided in a base end portion of the arm. When the manual feed tray in the side surface of the housing is opened, the arm rotates around the conveyance roller as a fulcrum through the frame linked with the manual feed tray by the link. Thus, the feed roller projects to the outside of the housing, and moves down onto the manual feed tray. On the other hand, when the manual feed tray is closed, the arm is inclined to have a posture with which the feed roller is lifted up. Thus, the feed roller unit is retained inside the housing.
JP-A-H11-171360 (FIGS. 3 and 4) is referred to as a related art.
In the configuration according to JP-A-H11-171360, the arm is retained in a posture with a large inclination angle in the position where the feed roller unit is housed, so that the occupied space can be reduced in the feed (paper feed) direction. However, the space can be reduced merely in accordance with the inclination of the arm itself. In order to expand the space to be occupied by the other units inside the housing or to miniaturize the housing as a whole, it is requested to further reduce the occupied space of the feed roller unit when it is housed.
In addition, in the feed (paper feed) using the manual feed tray as described above, it is also requested to make it easy to insert recording media to thereby improve the convenience of users.